 
 (defn- scope-bus-freq
   [s]
-  (let [buf (buffer SCOPE-BUF-SIZE)
+  (let [buf       (buffer SCOPE-BUF-SIZE)
         bus-synth (start-bus-freq-synth (:thing s) buf)]
     (assoc s
       :size SCOPE-BUF-SIZE

(defn- paint-scope [^Graphics g id]
  (if-let [scope (get @scopes* id)]
    (let [{:keys [background width height color x-array y-arrays slider]} scope
          s-val (.getValue slider)
          y-zoom (if (> s-val 49)
                   (+ 1 (* 0.1 (- s-val 50)))
                   (+ (* 0.02 s-val) 0.01))
          y-shift (+ (/ height 2.0) Y-PADDING)
          [y-a y-b] @y-arrays]
      (doto g
        (.setRenderingHint RenderingHints/KEY_ANTIALIASING RenderingHints/VALUE_ANTIALIAS_ON)
        (.setColor ^Color background)
        (.fillRect 0 0 width height)
        (.setColor ^Color (Color. 100 100 100))

  "Display scope window. If you specify keep-on-top to be true, the
  window will stay on top of the other windows in your environment."
  ([panel slider title keep-on-top width height]
     (let [f    (JFrame. title)
           cp   (.getContentPane f)
           side (JPanel. (BorderLayout.))]
       (.add side slider BorderLayout/CENTER)
       (doto cp
